Carbon black is composed of carbon, but is usually classified as an inorganic pigment. Carbon black is a black powdery substance in which hydrocarbons are incompletely burned or thermally cracked in the gas phase. Due to different production processes, various products with different properties can be obtained through different process conditions.
1) Microstructure of carbon black
Carbon black particles have a microcrystalline structure. In carbon black, carbon atoms are arranged in a manner similar to graphite, forming a hexagonal plane. Usually 3 to 5 such layers form a crystallite, due to each graphite layer of carbon black crystallites. In the middle, the arrangement of carbon atoms is ordered, and the arrangement of carbon atoms between adjacent layers is disordered, so it is also called quasi-graphite crystal.
2) Particle size of carbon black
The particle fineness of the pigment carbon black can be as low as 5 nm. In general, the carbon black particles are not isolated, but a plurality of particles are interpenetrated through the carbon crystal layer to form a chain branch. Different production processes can obtain carbon black particles with a wide range of particle sizes. The products obtained by the lamp black production process are relatively rough, and the gas black production process can obtain fine products.
The carbon black of almost all particle size ranges can be obtained by the furnace black production process, and the carbon black of the same variety has different particle sizes, and exhibits a particle size distribution range. In general, the finer particles have a narrower particle size distribution.